Attività

Vacuum contactor operation with parallel connection of independent consumers

This work presents a model of a transformer substation with parallel connection of independent consumers via vacuum switches. Several options of an

electric arc model are considered upon switching off a vacuum switch such as: KEMA model and "black box" model. Modern computer models of vacuum

switches were analyzed. Since the model data were not suitable for the conditions of the experiment, a simulation computer model was developed that reflects

the specifics of the operation of the substation and of the transition process upon disconnection of one or several vacuum switches. The results of the

developed methodology of analyzing transition processes were verified. To check the results of computer simulation, an experimental model was constructed, it

consisted of: an electric load (inductive nature), a power supply, two vacuum switches, and a measuring circuit. The circuit is switched on and off using a

pneumatic system controlled by a microcontroller. The primary purpose of the work is to check mutual influence of vacuum switches upon parallel

disconnection, since there may be a restrike caused by effects of switching overvoltage between neighboring switches upon irregular disconnection. The

effects of a transition process in one switch on the total current of the entire system were identified. A stand for a projected trial was demonstrated as

well.

With continuing development of science and technology, high voltage electrical equipment performance has been improved very fast, and dashed out some of

the new switch gear, for example, the F-C circuit. Through understanding and analyzing the principle, characteristic and function, etc of F-C circuit ,

describes its advantages in some areas relative to the circuit breaker, For example, the protection of a more timely, overvoltage lower, functions in line

with more reasonable; the lower cost for. Purpose is to allow engineers to correct reasonable selection of high voltage switch when used in the design and to

promote domestic F-C circuit development.

The design, operation and use are characterized for high voltage vacuum

contactors in underground coal mines endangered by methane and coal dust explosions. Design of a vacuum contactor is shown in a scheme. Vacuum contactors

are superior to electromagnetic contactors. Vacuum contactors have a reduced size and weight and are characterized by improved commutation properties. Under

vacuum conditions, intensity of electric discharges is lower than in an electromagnetic contactor. Reliability of vacuum contactors is 16 to 20 times higher

than that of electromagnetic contactors (90% of metal vapors caused by an electric arc settle on contact surface). No time consuming buildup removal or

cleaning is necessary. Optimizing contactor position in a power system in underground mines is discussed. Efficiency of using vacuum contactors and the RC

systems is discussed.

Vacuum contactor is an electrically controlled switch that is used to make or break an electrical circuit with the help of vacuum interrupter, relay, and

fuse. The drivers of the this market are influenced by the trends in the commercial sector and by the trends in the process and manufacturing industry.

Growth in the related as well as complementary markets, such as motors, capacitors, switchgear, and transformer, also contribute towards the growth of vacuum

contactors.